Zuma spacecraft launched by SpaceX is lost after it was unable to reach orbit.

A secret spacecraft, launched by a SpaceX rocket on Sunday failed to reach orbit and was lost. The spacecraft called Zuma was launched at 8 p.m. on Sunday from Cape Canaveral Air Force Station in Florida.

However, the spacecraft apparently didn’t detach itself from the upper stage of the rocket as it was supposed to do and was therefore unable to reach a stable orbit, according to a U.S. administration official and two sources who were briefed on the matter. The sources did not confirmed what exactly the payload was, saying that it was classified information.

The mission itself took place in complete secrecy even before it failed to reach orbit.The government agency that ordered the spacecraft has not been disclosed. Northrop Grumman (NOC), the aerospace and defense company that built the Zuma spacecraft, only commented that “This is a classified program. We cannot comment on classified programs”. SpaceX has also declined to give details about the spacecraft.

It was not immediately clear that if the failure of this mission was due to problems with SpaceX rocket or with the Zuma’s spacecraft.SpaceX issued a statement on Tuesday stating that the rocket performed as designed.

Gwynne Shotwell, president and chief operating officer of SpaceX said in a statement that”After review of all data to date, Falcon 9 did everything correctly on Sunday night, If we or others find otherwise based on further review, we will report it immediately. Information published that is contrary to this statement is categorically false. Due to the classified nature of the payload, no further comment is possible.”

Because of Zuma’s secrecy, SpaceX didn’t live stream the entire mission as it typically does.However, it did show both the launch and the landing of the first stage of the Falcon 9 rocket back at Cape Canaveral.

This is not the first time that a SpaceX rocket has lost a payload. On September 1, 2016, a SpaceX Falcon 9 rocket exploded while preparing to test its engines, which destroyed the Amos 6 communication satellite that was on the top of the rocket and was to be used by Facebook. Another SpaceX rocket exploded in 2015, which was carrying supply mission to the International Space Station for NASA.However, the company has completed more than ten successful supply missions to ISS.

The loss of a government payload comes at a bad time for SpaceX as It has been competing with other private companies to launch more military payloads and it plans to carry its first astronauts into space in its Dragon space capsule later this year. Since the last Space Shuttle flight in 2011, NASA has relied upon the Russian space agency to carry U.S. astronauts to the ISS.